With the rapid development of the business and the government's control over energy, based on the implementation of energy-saving emission reduction and environmental protection policies, the dealers' requirements of the lighting control system are increasing. The existing constant illumination control system on the market is based on the illumination of the sensor location, not the illumination of the target area. It can control the overall illumination level of the space, but cannot control the target area to achieve constant illumination. However, in the application of commercial lighting, there is a new requirement to control the illumination of the working table. The well-known TRIDONIC light sensor based on DALI system in the industry can only control the overall illumination of the space so as to save electricity to a certain extent, but it cannot meet the requirement for controlling working table to achieve constant illumination.